In today's web performance industry, one example measurement standard for page load time (PLT) is based on determining a start rendering time and finish rendering time. Start rendering time in this PLT measurement standard is defined as the time when a web page starts rendering something on the computer screen. Finish rendering time in this PLT measurement standard is defined as the time when a web page finishes rendering all the content of the given web page on the computer screen. Finish rendering time is also referred to as above folder time (AFT). Another example PLT measurement standard is referred to as time to last byte (TTLB).
These above example PLT measurement standards can be employed with many static web pages which do not have significant rich content and/or content changing dynamically after the content gets downloaded. Web sites, however, are increasingly getting fancier with more rich content and more dynamic content (e.g., dynamic images, videos, Adobe Flash content, etc.). The above example PLT measurement standards are not easily employed with rich content and/or dynamic content web pages and the measurement results can be ambiguous.